Toy mechanical scoop



July 29, 1952 J. B. LOBB TOY MECHANICAL sc001 Filed March 22, 1949 5Sheets-Sheet l Mm mm sw WW 9% w% July-29, 1952 J. B. LOBB TOY MECHANICALSCQOP' 5 Sheets-S'neet 2 Filed March 22, 1949 J. B. LOBB TOY MECHANICAL5000? July 29, 1952 Filed March 22, 1949 5 Sheets-Sheet 5 MENTOR, JOHN BL 053 y s I I u Jira.5.

July 29, 1952 5 Sheets-Sheet 4 Filed March 22, 1949 J 29, 1952 Y J. B.LOBB 2,604,726

' TOY MECHANICAL SCOOP Filed March 22, 1949 S Sheets-Sheet 5 PatentedJuly 29, 1952 OFFICE TOY MECHANICAL SCOOP John Buchanan Lobb, Southgate,London, 7

England Application March 22, 1949, Serial No. 82,855 In Great BritainMarch 19, 1948 13 Claims.

This invention has reference to mechanical toys or models. The primaryobject of the invention is to provide an improved toy in the form of amechanical load lifting device such as a crane, grab or scoop in which anumber of operations necessary for the transference of a load from oneplace to another are carried out by means of a power source such as aspring or electric motor carried "by the device, the operations beingautomatically effected in correct sequence and timing. A further objectof the invention is to provide a device in the formof a toy or model asabove set out in which the device includes a grab, bucket or pick uphook which is carried by a wheeled, tracked or other mobile structure,the sequence of operations including intermittent movement of the saidstructure, the pick up and discharge operations being performed whilstthe structure is stationary, the device realistically simulating thenormal'action of the full size load lifting device.

The device according to the invention may be in the form of a stationaryor fixed platform, but the invention further contemplates the employmentof a mobile platform or member, the geap ing from the main power sourcebeing coupled to the driving wheels orother members through a suitablemechanical device such as a cam and linkage actuatedby the power sourceto impart an interrupted drive to the platform. It will be understoodthat the pick up and unloading operation occurs while the platform isstationary and the arrangement may be such that the platform movement isunidirectional or is reciprocatory.

Preferably, the power source consists of a clockwork motor but saidpower source could be an electric motor or a steam engine. The inventionmay be applied to a device in which the pick up member consists of ascoop, or said member may be a hook, or agrab bucket, i. e. a bucketconsisting of two'partspivoted onacommon-center .line, the parts.opening and closing jaw fashion, the mechanism including means foropening and closing .Lthe jaws at the appropriate times in the cycle ofoperations, or said member could be an electro-magnetic device.

In order that a clearunderstanding of the invention may be obtainedreference will now be made to the accompanying drawings illustrative ofpreferred forms of the invention, wherein:

Figure 1 is a sidevi'ew of one form, wherein the cabin is mounted onafixed base to turn on a vertical axis,- the jib arm being shown in theloading or pick up position;

Figure 2 is a view looking from the left hand side of Fig. 1 with thecabin turned through The arm where shown in full lines is in thedischarging position and where shown in broken lines in the normal orcarrying position;

Figure 3 is a plan view of the operating mechanism;

Figure 4 is a sectional view on the line IV-IV,

Figure 3; V v

Figure 5 is a plan view showing an alternative mechanism for use with amobile crane or the like wherein in addition to cabin turning and jibmovement, the wheeled mounting platform is driven so as to move back andforth during appropriate periods in the cycle of operations;

Figure 6 is a sectional side view on the line VL-VI Figure 5; s

Figure '7 is a fragmentary side view of an alternative mechanism inwhich the wheeled plat form has an intermittent unidirectional movementimparted thereto; V

Figure 8 is a sectional view VIII-VIII Figure 7, and

Figure 9 is a side or general represent either of the forms of theinvention utilising a wheeled platform.

Like reference numerals in the drawings indicate like or equivalentparts, and referring firstly to Figures 1 to 4, the constructionillustrated includes a fixed base or supporting part II) on which ismounted a cabin II, said cabin housing the operating mechanism and beingmounted for turning movement on the upper surface of the base I0,turning on the vertical spindle I2 with a ball race I3 concentric withthe spindle I2 interposed between the underside of the cabin and the topof the platform. 1

The turning movement of the cabin on the vertical axis is obtained bymeans of a series of equally spaced holes I4 which series is arranged onan arc concentric with respect to the vertical turning axis of thecabin. The holes of the series are for engagement by the teeth of thepinion I5 driven by the shaft I6 as later described, whereby as the saidpinion turns, the cabin turns about its vertical axis. I 1

A clockwork or spring motor I! is mountedin the cabin II on a horizontalaxle I8. Theoperating mechanism is supported by the parallelside platesI9, I9, said mechanism including the axle I8, the main cog 20 and thegear train consisting of the pinions 2I, 22, 23, 24, 25, 2B, 21, and 28arranged in coaxial pairs, the wheel 28 forming in combination with thepivoted member 29 an escapement which, controls the speed of rotation ofthe gear train. ,The lever 4| acts as brake;

on the line 1 view which may of the cam 30 during its full rotation. Theend.

of the horizontal arm of the lever has a slot 36 therethrough in which apin 31' on the CO5; 38: engages, said cog being carried by a spindle 39and meshing with a cog 40 carried by. thespindlel6. at one side (Fig. 3)and has the pinion l5 mounted thereon the teeth of which pinion areshaped to engage in the arcuately arranged row of holes [4. Startingattheposition. shown in Figs; 1 and 4; with theaxlel8' rotating,the'cam. 3.6. during its rotation rocks the lever 32;.whichmovementthrough the slot and? pincoupling 3.6, 35?, turns the. cog 38' andthereby turns the pinion l5 through the cog 40. The rise of the cam' 30is sufiicient to give a turning movement of the cabin of approximately90, whereupon the: arm end 34 rideson the cam edge part' 3% which isarcuate with respect to the axis of rotation of the'cam so that thelever 32' is stationaryand consequently thecabin does n'ot turn until:the end 34 commences to rideon thefall of thesaid' cam. The movement ofthejib arm 42 occurs whilst the cabin is stationary, saidjib armmovement being controlled by the cam 31 and link.- age. The jib-arm ispivoted by a pin 44' on the transverse axis-of the cabinbeing urged bythe coil spring 45 around' the pin into its maximum up-swung position.The linkage comprises two arms 46, 4T, pivoted together at 48' with the.one arm 46 at its lower end loose. on the spindle 33, theother arm4Tbeing pivoted to the one side of the-jib-arm. In the position shown inFigs. 1'

and 4, the arm 42 is lowered-to its maximum extent andas the cam 31rotates; the pin on the arm 46 (which pin bears-on the edge-f cam 319rides on thecam surface resulting inthe lifting of the jib arml- Thepickup bucketSD-is connected to the jib arm by a cord 51 anchored atoneend at 52, then passingaround the pulley'53, back and over the doublegrooved pulley'54, around the bucket pulley 55, back over thepulley- 54,and is anchored at its other end at 56. A second cord B-Tis con-- nectedat one end to the-rear ofthe bucket, and

passes-over the pulley 581 and its other end is connected to theupper'end' of the lever- 58. Said lever 59 ispivot'ed in a-yolie-Bilfixed to themotor crossbar 61 and the inner face-of the gear 2%) has apin 62' thereon. With this arrangement, for each revolution of'the axleI22 i. e. once every cycle of operations, the lever- 53 is rocked incounterclockwise direction Fig. 4 by the pin 62- so that the rear end ofthe bucket i's'rai'sed to tip said bucket.

The mechanismin the first embodiment shown is timedtooperateas'follovvs:

Assuming the" partsare i'n the position shown in Figs. 1', 3= and 4',then the bucketisin its loading position. As the'axle l8 rotates, thejib arm first swings upwardly, under the action of the cam 34 andit's-associated: linkage, and the cam 30; throughitslever 3 2 and-geartrain and arouate rack l4 turns the cabinthrough'approximate- Thespindle l6 projects beyondtheplate [-9.-

' ward and back movement to the chassis.

4 ly 90 to the position shown in Fig. 2. It will be seen that the jibarm rises prior to the cabin turning movement i. e. into the positionshown in broken lines. After the cabin has stopped turning, continuedmovement of the cam 3| results in movement of linkage 46, 41 to lowerthe jib arm, and when lowered, the pin 62 on the gear. wheel 20has-.move'diintoa position to rock the lever 59; so raising 'therear' ofthe bucket or scoop and tipping same, the parts being in the positionshown by full lines Fig. 2.

Referring now to the construction which is illustrated in Figs. 9, and6, and in particular to the latter two figures, the cabin is mounted ona vertical axis for turning on the platform a which platform comprises achassis structure mounted ontwo pairs of wheels 63, 63, and E4, 54, therear pair 54 being driven to impart a for- The wheels may be coupledbyan endless track or band. at" each; side. Thewgear. wheel 20. in thiscase' is;formed' on: its:one.face witha cam ring 65,andalso.mountedwithinthering and driven by the axle. lflcis'the; cabinturning cam 30. This latter-cam; iscoupledi through: the elbow arm 32aand? pin 3'40; to a.crank;66, theend of whichengages; in the: slot 3.6a,whereby onthe rocking of the arm, the arcuate. contrate gear wheel 6'!is turned, said gearJbeing coupled. to a cog E8'on a vertical spindle;69. Beneath: the. cabin base is the; gear wheel. lilalso; mountedxon thespindle.

39, saidxwheelfldmeshing withtherack'llia concentric. with. respect tothe vertical cabinmounting spindlelZi The. spindle l2'in;this;embodimenthas a bevel wheel ll. onits: upper: end and a similar wheel 12at'itsxlowerend,.which:wheel l2'meshes with the bevel wheel-13; keyed.to: the shaft. 6.4a.

The. drive to the bevelwheeli II. is through'the bevel wheel. M mounted.on the spindle 5 to which drive is imparted by. the cog 16' mountedonsaidspindle' ThezcamringfiE is utilised to control the drive'to' thecog 16, so that said cog canibe' stationary'(during.the major part ofthe'jib arm movement): or turn in one direction for forward. chassismovement, or turn in the opposite direction; for: rearward. chassismovement. This. reverse movement maybe imparted by'any suitablemeanssuchas adog clutch mechanism, but preferably the movement is imparted bythe pair of" pinions 11, Ha mounted on a cradle 18.freely'pivotedzonthespindle 15, the cradle: being rocked by the cam sothat both pinions 1.7, Ila: can be. free from engagement with pinionsZZ,respectively in the gear train which in this case. mesh and areidentical to travel: at. the same peripheral speed, or pinion 11 can.mesh with pinion 22 or (as shown in Fig. 6) pinion .ll'a meshes withpinion 24.

The coupling betweenithe cam ring and the cradle is through. a crankediarm 79 having a pin 80' atiits' upper end'to engage the cam ring whicharm 19 is also coupled to said cradle by the pin/8t on. the cradle andslot 82 in the arm end, the arm 79. being" pivoted to the plate l9 at83. The said pin 80' isconstrained to follow the outward curves of thecam. track 35 to couple the drive. to, and 'uncouple the drive from thewheels, byv virtue firstly'of the path formed between said curve andthecam 30, and secondly by virtue of the path formed between theabutment 84 and the said curve. In this embodiment the gear traincomprises the pinions 2|, 22, 24, 25, 26, 21 and 28, the speed beingcontrolled by the escapement'29. It-will be clear that 'pinions 22 and24 travel at the same speeds but in opposite directions.

The mechanism for operating the jib arm is conveniently the same asdescribed with refer ence to the first embodiment, and in the positionshown in Figs. 5 and 6, the drive is coupled to the rear wheels, the pin80 being in the operative section between abutment 84 and cam track sothat the platform is moving forwardly, until the pin 80 leaves thedepressed cam part whereupon the drive to the wheels is broken. It willbeunderstood that the drive to the wheels is coupled up only when thepin 80 is in the one or other of the two operative sections abovedefined, that is to say, the platform is stationary when the pin 80rides on the two sections of the cam which are concentric with itscenter of rotation or plain sections. As the pin 80 commences to ride onits approaching first plain section, and durin the period it rides onthis section, the jib arm is lowered by the cam and pin arrangement 3|,49 and associated levers, as described with reference to the previousembodiment. The cabin remains stationary with the jib forwardlyextending, when the said jib is moving, the cam 3| being located on itsshaft [8 in suchan angular position that the jib arm rises before thepin 80 runs on its next operative cam part adjacent the larger radiussedpart of cam 30. I

When the gear to the rear wheels is next coupled up, the structure movesrearwardly, un-

til the pin leaves theoperative cam part aforesaid. The cabin is nowturned on its axis, as the pin 34a now leaves-the smaller radiussed partof the cam 3| and on or just before the cabin completes its movementaforesaid (the pin 34a now riding on the larger radiussed part of itscam 31!), the jib arm is lowered. In this case, at the completion of thelowering action the: scoop is tipped and the jib arm then rises,whereupon the cabin is returned as thepin 34 is now riding on its camsection from the larger radiussed part to the smaller radiussed part,and at or about the instant cabin stops and the pin 34a;commences toride on its smaller radiussed part the pin 80 enters the operative campart between the cam and the abutment 84.

It will be understood however, that the cam and actuating members may bearranged to produce any desired sequence of operations.

In the modification illustrated in Figs. 5, 7 and 8, an arrangement isshown wherein intermittent forward movement is imparted to the wheeledplatform. In this case, the outer face of the gear 29 is formed as a camtrack 85, and a rod 86, each end of which is bent as at 81, B8,issecured to the plate l9 by brackets 89, 89, whereby said rod can beturned on its axis. Theend 81 projects upwardly to engage the cam track85, whilst the end 88 is coupled to the groove 90 formed by a bossbetween the flange 9! and the pinion 92. The said pinion is loose on theshaft 15, on which the bevel gear or pinion 14 is keyed, the couplingbetween pinions T4, 92 being made by the teeth 93, 93a. 4

When the arm end 8'! rides on theithick part of the cam rim, the pinion92 is in the-position carries a pick-up bucket or'scoop, but it will beclear from the foregoing description with reference to the drawings thatother forms of pick-up devices could equally well be used. Thus, a twopart grab could be provided, the cord 51 being connected to the pivotedtogether parts so that the rocking of the lever'59 by the pin 62 movesthe cord to open and close the grab at the appropriate points in thecycle of operations.

I claim:

1. Toy or model mechanical load lifting device comprising a base, acabin pivoted on the base about a vertical axis, a jib arm fulcrumed onthe cabin, a pick-up device carried by the jib arm, a power source onthe'cabin, operable means on the cabin cooperating with the base androtating the cabin on the base from one position to a second and back,second means driven by the power source and operating the first meansfor source and swinging the jib arm up and down While the cabin is inits first position and swinging the jib arm down and up while the cabinis in its second position, fourth means lowering the pick-up devicerelative to the jib arm during the upward swing thereof and raising thepickup device relative to the jib arm during the down swing thereof, andfifth means driven by the power source and lifting the rear end of thepick-up means when the jib arm is in lowered position in the secondcabin-position.

2. A toy or-model mechanical load lifting device such as a grab or cranecomprising a supporting platform, a cabin mounted on'a vertical pivotaxis on said platform, a power source carried by said cabin, a jib armcarried by said cabin and mounted for swingingraising and loweringmovement thereon, gearing between said power source and a drive betweenthe cabin and platform for effeoting the turning of the cabin on itspivot axis,

cam mechanism actuated by the power source and operatively coupled tothe said gearing to effect the turning of'the cabin from one position toa second position, and a second cam mechanism actuated by the said powersource, which second mechanism is operatively coupled to the jib arm toefiect raising and lowering thereof, the two cam mechanisms beingtimed'so that the major portion of the jib movement to effect loadpickup and dischargeis obtained when the cabin is in one or other of itsstationary positions.

3. Toy or model mechanical load lifting device comprising a supportingplatform, a cabin mounted on a vertical turning axis on said platform, ajib arm carried by said cabin ona horizontal pivot axis, a power sourcecarried by the cabin, a main spindle in the cabin driven by said powersource, a cam on said spindle, a linkage couplingsaid cam to a pinion,which pinion is coupledto a radial driving'rack on the platform, saidcam having two operative sections for cabin turning movement from a pickup position to a discharge position, with non-operative sectionstherebetween, a jib arm operating cam on said spindle, a linkagecoupling said jib arm operating cam to the jib arm, said jib armoperating cam having two operative sections for jib arm lowering andraising during non-cabin turning periods, with a pick up device carriedby said jib arm.

4. Toy or model mechanical'load lifting device comprising a supportingplatform, -a cabin' mounted on a vertical turning-axis on said platform,a jib arm carriedby said cabin on a horizontal pivot axis, a'power'source carried by the.

cabin, a= mainspindle; in thez-cabin driven;by saidpowersource,- a--cam' on: said spindle, a linkage coupling; said cam. to.a1pinion,;whicl'i pinion is coupledto aradia'l, driving rack-:onitheplatform, saidicam having two operativesections for cabin turningmovement. from a, pick up position to a discharge position, with:non-operative; sections therebetween, a jib. armoperating; cam on. saidspindle, a linkage coupling said jib arm operating, cam to. they jibarm, said jib arm operating cam having; two. operativesections for'jibarm lowering, and raising during; non.cabinturning periods, witha pickup device. carriedby said jib arm andmeans driven by the. power sourcefor operating; the: pick up deviceduring jib arm movement.

5. Toyormodel mechanicalload lifting device comprising; a supporting,platform, a cabin mounted on..a verticalturning axis orrsaid plat.

form, a jib arm carried by saidicabin. on a horizontal pivotaxis, apower source carried by the cabin, a. mainv spindle inv the: cabindriven by saidpower source,.a camon said spindle, a linkage couplingsaid cam to a pinion,which.pinion is coupled toa radial driving; rackonthe platform, said cam. having; two operative sections for cabinturningmovementfrom a pick up position to a discharge position, withnon-operative-sections therebetween, a; jib arm operating cam, on saidspindle, a linkagecoupling said'jib-arm operating cam to theijibarm,said.jib arm operating cam having two operative sections for jib armlowering and raising during non-cabin turning periods, witha pick updevicecarried by said jib arm and means driven by the-power source foroperating the pick up device during jib arm movement, said pick" upvoperating means comprising a pulley guided cord connected at oneend tothe pick up device and at the other end to the cabin, the powersourcecoupled to said cord by a linkage connected to the power source,which linkage is operated during stationary periods of the cabin.

6. A toy or model mechanical load lifting device such as a grab or cranecomprising a supporting platform, a cabin. mounted on a vertical pivotaxis on said platform, a power source carried by said cabin, a jib armcarried; by said cabin and mounted for swinging-raising and loweringmovement thereon, gearing-between said power-source anda drive betweenthe cabin and platform for effecting the turning of the cabin on itspivot axis, cam mechanismv actuated by the power. source and operativelycoupled to the said gearing to effect the turning of the cabin from oneposition to a second position, and a second cam mechanism actuated bythe said power source, which second mechanism is op-eratively coupled tothe jib arm to effect raising and lowering thereof, the two cammechanisms being timed so that the major portion of the jib movement toeifect load pick up and discharge is obtained when the cabinis in one orother of its stationary positions, a wheeledmounting for said platform,gearing between the power source, and the wheels for rotating same, andmeans actuated by the power source for interrupting the drive duringcabin turning and jib arm movement.

7. Toy or modelmechanieal load lifting device as claimed in claim 6, inwhich the drive to the wheels is unidirectional.

8; Toy or model mechanical load lifting device as claimed in claim 6, inwhich the drive to the wheels is reciprocatory,

9. Toy or model mechanical load lifting device comprising: a.supporting" platform, a cabin mountedon avertical; turning axis on saidplatform, a jib arm carried by said cabin on-a,h0ri zontal pivot axis,a. power source carried by; the

cabin, a mainspindle inithe cabin driven by'said.

power, souree, a cam on said spindle, a linkage coupling said cam to apinion, which pinion is coupledto aradial driving rack on the platform,

said cam havingtwo operative sections forcabin.

turning movement from a pick up positionto a discharge, position, withnon-operative sections therebetween, a-jib, arm operating cam on saidspindle,,a linkage couplingsaidjib arm operating cam to thejib. arm,said jib. arm operating cam having twooperative sections forjib armlowering" and raising during non-cabin turning periods,

witha pick updevice carried. by said jib arm,

means driven. by thepowersource for operating the pick up device-duringjib arm-movement, and, and a wheel, drive-control, cam on said main.

spindle, which; camiscoupled through. linkage tov an interrupting gearto the wheels.

10.. Toy or5model.mechanical'load'liftingdevice comprising a supportingplatform,

form, a jib arm carried by said cabin on a horie zontal' pivot axis; apower source carriedby-the cabin, a main, spindle-in the cabindriven bysaid power source, a camon said spindle, a linkage coupling said cam toa pinion, which pinion is coupledjto a radial driving rack, on theplatform, said cam havingtwov operativesections for cabin turningmovement, from apick up position to a discharge position, withnon-operative sections therebetween, a jib-arm operating cam on said.

spindle, a" linkage coupling-said jib arm operating cam to the jib-arm;said jib arm operating cam having two operative sections for-jib armlowering and raising, during: non-cabin turning periods, with, a pickupdevice carriedby said jib arm, means driven by thepower source foroperating the pick up device during jib arm movement, and a wheel-drive.control cam' on said mainspindle, which cam is coupled through linkageto an interrupting gear to the wheels, said interrupting drivecomprising a clutch.

11.. Toy ortmodel mechanical loadliftingidevice comprising a supportingplatform, a cabin mounted on a vertical turning axis on said platform, ajib armcarried by said cabin on a horizontal pivot axis, a power sourcecarried by the cabin, a main'spindlein the cabin drivenby saidpowersouree, a cam on said spindle, alinkage coupling said cam to apinion, which pinion is coupled to a radial driving rack on theplatform, said cam having two operative sections for cabin turningmovement from apick up position to a discharge position, withnon-operative sections therebetween, a jib arm operating cam on saidspindle, a linkage coupling said jib' arm operating cam to the jib arm,said jib arm operating cam having two operative sections for. jib armlowering and raisingduring non-cabin turning periods, with-a pickupdevice carriedby said jib arm, means driven by the power source foroperating the pick up device during jib arm movement, and a wheel drivecontrol cam on saidv main spindle, which. cam iscoupled through linkageto an-interrupting gear to the wheels, said interrupting drivecomprising a reverse gear having aneutral position, and the wheel drivecontrol cam operates said gear to effect forward, reverse and stop ofthe platform.

12. Toy or model mechanical'load lifting device comprising; asupporting, platform, a cabin mounted ona vertical turning axis onsaidplata cabin, mounted ona vertical turning axis on said plat-- form,a jib arm carried by said cabin on a horizontal pivot axis, a powersource carried by the cabin, a main spindle in the cabin driven by saidpower source, a cam on said spindle, a linkage coupling said cam to apinion, which pinion is coupled to a radial driving rack on theplatform, said cam having two operative sections for cabin turningmovement from a pick up position to a discharge position, withnon-operative sections therebetween, a jib arm operating cam on saidspindle, a linkage coup-ling said jib arm operating cam to the jib arm,said jib arm operating cam having two operative sections for jib armlowering and raising during non-cabin turning periods, with a pick updevice carried by said jib arm, means driven by the power source foroperating the pick up device during jib arm movement, and a wheel drivecontrol cam on said main spindle, which cam is coupled through linkageto an interrupting gear to the wheels, said interrupting drivecomprising a reverse gear having a neutral position, and the wheel drivecontrol cam operates said gear to effect forward, reverse and stop ofthe platform, said reverse drive comprising a pair of pinions carried bya rockable cradle to which movement is imparted by an arm actuated bythe cam, said pinions meshing with a common pinion on a shaft coupledthrough bevel gears to the vertical shaft, the said cradle taking up oneof three positions as determined by the cam, one said position meshingone pinion of the pair with a wheel in the gear train to turn the commonpinion in one direction, a second position meshing the other pinion ofthe said pair with another oppositely rotating wheel in the gear trainto turn the common pinion in the opposite direction, the third positionbreaking the mesh of both said pinions from the gear train.

13. Toy or model load lifting device comprising a wheeled platform, acabin mounted on said platform on a vertical spindle, a power sourcecarried by the cabin, gearing driven by said power source and coupled tothe wheels, a cam driven by the power source and operatively coupled toa reverse and interrupting gear in the said gearing, a jib arm carriedby the cabin, a cam driven by the power source and operatively coupledto the jib arm through mechanism for raising and lowering said jib arm,a cabin control cam driven by the power source and operatively coupledto a gear for effecting the turning of the cabin from a pick up positionto a discharge position, said cam for controlling the reverse gearmoving the cabin forwardly to the pick up position, said cam for the jibarm movement lowering the jib for the pick up operation in the forwardposition, said cam for controlling the reverse gear coupling up the saidgear for reversal after pick up operation, said cabin control cameffecting cabin turning movement in the rearward position, the jibmovement cam lowering the jib arm for discharge in the rearward positionof the cabin and subsequently effecting the rising of the jib arm, saidcabin control cam returning the cabin, in which position said gearcontrolling cam couples up the drive for forward movement of theplatform.

JOHN BUCHANAN LOBB.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 2,020,802 Sauer Nov. 12, 19352,147,973 Ekbom et a1 Feb. 21, 1939 2,466,619 Stuckey et a1 Apr. 15,1949 2,512,166 Merrill June 20, 1950

